1. Field of Invention
This invention concerns a method for long range transport of fresh chilled meat. Particularly, this invention concerns a transport of vacuum packaged chilled beef, lamb or poultry meat or fish in refrigerated containers wherein one part of the container is filled with the frozen meat and the fresh non-frozen but chilled meat is placed in the close proximity of the frozen meat and insulated with foamed polystyrene laminated on both sides with aluminum sheets of insulated material and wherein there is controlled atmosphere within the insulated compartment.
2. Background Art and Related Art Disclosures
Long distance transportation of fresh meat has always presented a challenging problem. Originally, meat was processed by salting, drying, smoking or by other methods. However, these methods greatly impair the taste and utility of the meat. With an advent of refrigeration, the preservation of the meat became somehow easier but the transportation over the extended time disallowed the transport of fresh non-frozen meat. This problem is particularly apparent for long range transoceanic transport of fresh meat.
A revolutionary milestone in refrigerated transportation was the development of highway trailers or TOFC (trailer on flat car) which allowed the disconnection of the trailer from the car (tractor) and delivery of the cargo by road, rail, sea or air without exposing it to unfavorable environmental conditions. The marine version of this container which Was developed in the 1960's relieved the steamship companies from constructing inflexible and expensive refrigerated ship. Airfreight of meats and fish, as well as other perishable foods was developed in post World War II and provided fast transportation but uses ice, dry ice, and insulated packages, as needed. Short delivery time and flying at high altitude where temperatures are cold enable airlines to deliver perishable goods without mechanical refrigeration. However, temperature control of meats and fish is not accurately controlled. The latest development in refrigerated transportation is the superchill technology which utilizes microcomputer-controlled linear inverter rotary compressor, which constantly adjusts its r.p.m. in response to temperature demand. This system was found superior to off/on control of standard compressors. Dual refrigeration coils minimized temperature to fluctuation during defrost cycles. A modified atmosphere system is also built into the container. However, maintaining the gas composition for long periods of transportation or storage is still highly inaccurate.
The major issue in long range refrigerated transportation remains the many specific requirements of the various foods when chilled or frozen. There are major difference in transporting chilled cut flowers, vegetables, fruit, red meat, fish, poultry or a variety of frozen foods. The refrigerated container and truck companies have problems in efficiently scheduling the shipment of a variety of products back and forth with the most appropriate containers. In the United States, only 50% of the containers can maintain temperature at -15.degree. C. and very few superchill containers are available. These containers are much more expensive and it is wasteful to use them for other purposes. Furthermore, as containers become larger and larger, that is 20, 40, and 45 feet long--many users cannot fill them with one product only. Therefore, container temperature is a compromise of the specific needs of the various products.
Since the frozen meat looses many of its qualities, it has long been an aim of meat processing plants and transportation companies to develop the new refrigeration system which would allow the transportation of fresh meat over long distances. Refrigeration containers having a regular refrigeration technology have been developed and used. These regularly refrigerated containers, however, have many problems. First, due to the switching on/shutting-off of refrigerator generator, there is a certain degree of fluctuation (within 3.degree.-5.degree. C.) of the temperature within the container. Due to the condensation and the water evaporation, which occurs only in carcasses where there is no packaging, ice forms in between packages of meat or in meat, causing so called "cold spots", that is a certain degree of freezing in places where the ice crystals form. Through the container's doors, certain degree of heat and humidity penetrates to the inside of the container, particularly during the loading and during transportation.
It would, therefore be of utmost importance to have available method including containers which would prevent the fluctuation of the temperatures within the container, formation of the ice or uneven refrigeration due to switching on/shutting off refrigeration system, evaporation, penetration of heat and the effects of loading.
Recently, the method for transportation of combined chilled and frozen venison meat was presented at the 33rd Annual Meat Science Institute Conference in Athens, Ga., Apr. 14-17, 1991. The method comprised placing the vacuum packages of chilled venison meat in standard frozen food containers which were also packed with frozen venison meat. The venison meat retained high quality, and palatability and low microbial counts, and rancidity. However, it is a general knowledge that venison meat is one of the most stable meats which can withstand, without spoilage, long range transportation in regular refrigerated container for about 4 weeks although quality and palatability have deteriorated significantly.
Other red meats such as beef, pork or lamb as well as poultry or fish are, however, much more sensitive to spoiling having more shorter shelf life generally around 1-2 weeks when kept fresh and chilled in standard refrigerator. It would thus be greatly advantageous to have available a method which would extend the shelf life of fresh chilled meat for at least 8-10 weeks, typically needed for storage, transcontinental transportation and particularly for transoceanic transportation.
It is therefore, a primary object of this invention to provide a method for long range transcontinental and transoceanic transportation or extended storage period.